Short answers, pulled from the story.
Plastic is made of synthetic or semisynthetic materials composed primarily of polymers, long chains of repeating units built from monomers. Most plastics are produced from natural gas and petroleum, though a growing minority come from renewable resources like polylactic acid. The polymer chains are usually carbon-based, sometimes with oxygen, nitrogen, or sulfur attached.
Leo Baekeland invented the world's first fully synthetic plastic, Bakelite, in New York in 1907, and he coined the term plastics. The first man-made plastic overall was Parkesine, invented by Alexander Parkes in 1855 from cellulose treated with nitric acid.
Between 1950 and 2017, an estimated 9.2 billion metric tons of plastic were made, with more than half produced since 2004. In 2023 alone, preliminary figures indicate over 400 million metric tons were produced worldwide.
The largest use for plastic is packaging, which makes up about 40% of its usage, followed by building and construction at about 20%. Other major uses include automobiles, furniture, toys, textiles, and electronics.
Of all the plastic discarded so far, less than 10% has been recycled and some 14% has been incinerated. Most plastic ends up in landfills or as pollution, and almost all recycling is done by simply remelting used plastic into new items.
Plastic decomposes slowly in natural ecosystems and most of it is never reused, so much ends up as pollution including marine garbage patches and microplastics. Additives can leach out and bioaccumulate in organisms, and in 2023 a disease called plasticosis, caused by ingesting plastic, was discovered in seabirds.
Thermoplastics do not change composition when heated and can be melted and molded repeatedly, including polyethylene, polypropylene, polystyrene, and polyvinyl chloride. Thermosetting polymers take shape only once and decompose rather than melt if reheated, with examples including epoxy resin, polyimide, and Bakelite.